The progestogen in the combined contraceptive patch
Norelgestromin
The progestogen hormone in the combined contraceptive patch, worn on the skin to prevent pregnancy.
What is Norelgestromin?
Norelgestromin is the progestogen (a synthetic form of a female hormone) contained in the combined contraceptive patch, where it is combined with an oestrogen (ethinylestradiol). The patch is stuck to the skin and changed weekly to prevent pregnancy. As a combined hormonal contraceptive, it carries a small increased risk of blood clots (in the legs or lungs, called VTE), like the combined pill. It can also cause skin reactions where the patch is worn, and it may be less reliable in people above a higher body weight. It is prescribed after checking it is suitable.
Education and reference only. This is a plain-language guide to Norelgestromin — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Norelgestromin is a progestogen, a man-made version of a natural female hormone, and it is the progestogen part of the combined contraceptive patch. In the patch it is paired with an oestrogen (ethinylestradiol), so together they make a combined hormonal contraceptive worn on the skin. The patch is applied to clean, dry skin and changed each week for three weeks, followed by a patch-free week, to prevent pregnancy. It works in the same overall way as the combined pill but is absorbed through the skin rather than swallowed, which suits some people.
How it works
The hormones in the combined patch, including norelgestromin, mainly work by stopping the ovaries releasing an egg each month. They also thicken the mucus at the neck of the womb, making it harder for sperm to get through, and thin the womb lining. Because the patch delivers the hormones steadily through the skin, it keeps levels even between changes, which is why it only needs changing once a week. As a combined method containing an oestrogen, it carries the same general benefits and risks as the combined pill, including a small increased risk of blood clots.
Company & origin
Originated / developed by: Specialist manufacturer.
The progestogen hormone in the combined contraceptive patch used in the UK, worn on the skin together with an oestrogen.
Practical use
How to take Norelgestromin
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Apply the patch to clean, dry skin and change it on the same day each week for three weeks, then have a patch-free week.
- Rotate the patch site to help reduce skin irritation, and press it firmly so it stays on.
- Apply each patch on time; if it comes off or you are late changing it, follow the advice on what to do and consider extra precautions.
- Seek urgent help for signs of a clot, such as a painful swollen leg, sudden breathlessness or chest pain.
- Tell your prescriber if your circumstances change, for example if you start smoking, gain weight or are due surgery.
Weighing it up
Advantages & disadvantages of Norelgestromin
Advantages
- An effective combined contraceptive that only needs changing once a week.
- Absorbed through the skin, so it suits people who would rather not take a daily pill.
- Like the combined pill, it can make periods more regular and lighter for some people.
Disadvantages
- Carries a small increased risk of blood clots, like other combined hormonal contraceptives.
- Commonly causes skin reactions where the patch is worn.
- May be less reliable in people above a higher body weight.
Practical use
Good to know
The most important safety point with the combined patch is that, like all combined hormonal contraceptives, it slightly increases the risk of blood clots in the legs or lungs (venous thromboembolism, or VTE); this risk is small but real, and it is higher in certain situations such as smoking over 35, being very overweight, after surgery or with a family or personal history of clots, which is why suitability is checked first. Learn the warning signs of a clot, such as a painful swollen leg or sudden breathlessness or chest pain, and seek urgent help if they occur. Skin reactions where the patch is worn, such as redness or itching, are common, and rotating the site helps. The patch may be less reliable in people above a higher body weight, which is discussed when choosing a method. Apply patches on time, and if one comes off or you are late changing it, follow the advice on what to do.
Who should not take it / use with caution
- People who have had a serious allergic reaction to the patch should not use it.
- It is avoided in people with a history of blood clots, certain heart or circulation problems, or some types of migraine (with aura).
- It is avoided or used with caution in people who smoke and are over 35, are very overweight, or have certain other risk factors, after checking suitability.
Monitoring
- Checking blood pressure and reviewing suitability before starting and at follow-up.
- Reviewing risk factors for blood clots, such as smoking, weight, migraine and family history.
- Discussing how the method is suiting you and watching for any warning signs.
Side effects
- Skin reactions where the patch is worn, such as redness, itching or irritation.
- Headache, breast tenderness, nausea and mood changes, especially in the first months.
- Irregular bleeding or spotting between periods, which often settles.
- Rarely but seriously, a blood clot in a leg or lung, signalled by a painful swollen leg or sudden breathlessness or chest pain, needing urgent help.
Key interactions
- Some medicines, such as certain epilepsy medicines and the herbal remedy St John's wort, can make it less reliable.
- Some antibiotics used for tuberculosis, such as rifampicin and rifabutin, reduce its effectiveness, so extra precautions are needed.
- Tell your prescriber about all your medicines, as some may need a different contraceptive approach.
Available as: A skin patch (transdermal patch) worn on the skin and changed weekly.
Answers
Norelgestromin: frequently asked questions
What is norelgestromin?
It is the progestogen hormone in the combined contraceptive patch, where it is combined with an oestrogen to prevent pregnancy.
How is the patch used?
It is stuck to clean, dry skin and changed on the same day each week for three weeks, followed by a patch-free week.
Does it raise the risk of blood clots?
Like all combined hormonal contraceptives, it slightly increases the risk of blood clots in the legs or lungs; this is small but is checked for before starting.
Why does my skin react where the patch is?
Skin reactions such as redness or itching where the patch is worn are common; rotating the site each time can help reduce irritation.
Is it as reliable if I weigh more?
The patch may be less reliable in people above a higher body weight, so this is discussed when choosing the most suitable method for you.
The wider class
About Progestogen in the combined contraceptive patch
Norelgestromin belongs to the progestogen in the combined contraceptive patch class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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